Building the New Mustang
Larry Jewett - April 09, 2014 02:49 PM
Efficiency was the goal of extensive aero testing on the 2015 MustangPhoto provided by Ford Motor Comapny
The bold, muscular form of the all-new Ford Mustang reimagines the iconic sports car shape in a way that retains the character that fans expect from the brand while incorporating aerodynamic technology that improves fuel efficiency and performance.
“Even with the classic, forward-leaning shark-bite grille and a more aggressive stance for the new Mustang, the aerodynamics team has made it slice through the air better for increased fuel efficiency while also keeping it planted to the road at higher speeds,” said Dave Pericak, Mustang chief engineer.
Aerodynamics plays an increasingly important role in overall vehicle performance as speed increases. The force required to slice through the air goes up exponentially with the speed, so twice the speed requires eight times the horsepower just to overcome drag. Small changes can have a big impact on both performance and fuel efficiency.
“We spent about twice as much time running aerodynamic simulations and doing wind tunnel tests than the previous Mustang,” said Carl Widmann, aerodynamics engineering manager. “Major advances in our computational fluid dynamics capability let us test the effect of design changes and give feedback to the studio in less than 48 hours so they had more opportunity to try out different styling ideas.”
Enclosing the wheels in skirts to smooth the flow doesn’t look right on a performance car like Mustang. Widmann and the aerodynamics team adopted a different approach, giving Mustang the first Ford application of wheel aero curtains.
Vertical slots in the outer edge of the front fascia channel air from the front of the car to openings in the wheel wells, directing it across the outer surface of the wheel and tire. The wall of high-speed air reduces drag while still leaving the beautifully designed alloy wheels fully exposed.
Active grille shutters will help make Mustang powered by the new 2.3-liter EcoBoost® engine even more fuel efficient by further reducing drag at higher speeds. The shutters can completely close off the grille, sending air over and around the car instead of through the engine compartment.
“We worked closely with the vehicle dynamics engineers that are tuning the chassis to make sure our experimental results for lift correspond to what they feel on the car when driving at the track,” said Widmann.
The overall air resistance is a combination of the frontal area and drag coefficient. Despite the wider rear haunches, the lower roofline contributes to a smaller frontal area. Along with a lower drag coefficient, the overall drag force of the new Mustang is slashed by an impressive 3 percent with better roadholding and less wind noise in the cabin. At highway speeds, three percent less drag will return about one percent better fuel efficiency.